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[2001:8b0:bb71:7140:64::1]) by smtp.gmail.com with ESMTPSA id m9sm850766wrx.55.2020.02.20.12.18.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Feb 2020 12:18:45 -0800 (PST) Received: from localhost (disaster-area.hh.sledj.net [local]) by disaster-area.hh.sledj.net (OpenSMTPD) with ESMTPA id 0fdb7f71; Thu, 20 Feb 2020 20:18:44 +0000 (UTC) To: Eric Blake , Max Reitz , qemu-block@nongnu.org Subject: Re: [PULL 06/18] qemu-img: Add --target-is-zero to convert In-Reply-To: <2c912ba1-998c-9ddb-55a4-c2ea1bb57edd@redhat.com> References: <20200220160710.533297-1-mreitz@redhat.com> <20200220160710.533297-7-mreitz@redhat.com> <2c912ba1-998c-9ddb-55a4-c2ea1bb57edd@redhat.com> X-HGTTG: disaster-area From: David Edmondson Date: Thu, 20 Feb 2020 20:18:44 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4864:20::341 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thursday, 2020-02-20 at 10:36:04 -06, Eric Blake wrote: > On 2/20/20 10:06 AM, Max Reitz wrote: >> From: David Edmondson >> >> In many cases the target of a convert operation is a newly provisioned >> target that the user knows is blank (reads as zero). In this situation >> there is no requirement for qemu-img to wastefully zero out the entire >> device. >> >> Add a new option, --target-is-zero, allowing the user to indicate that >> an existing target device will return zeros for all reads. >> >> Signed-off-by: David Edmondson >> Message-Id: <20200205110248.2009589-2-david.edmondson@oracle.com> >> Reviewed-by: Vladimir Sementsov-Ogievskiy >> Reviewed-by: Eric Blake >> Signed-off-by: Max Reitz >> --- >> docs/interop/qemu-img.rst | 9 ++++++++- >> qemu-img-cmds.hx | 4 ++-- >> qemu-img.c | 26 +++++++++++++++++++++++--- >> 3 files changed, 33 insertions(+), 6 deletions(-) >> >> diff --git a/docs/interop/qemu-img.rst b/docs/interop/qemu-img.rst >> index 42e4451db4..5f40137c10 100644 >> --- a/docs/interop/qemu-img.rst >> +++ b/docs/interop/qemu-img.rst >> @@ -214,6 +214,13 @@ Parameters to convert subcommand: >> will still be printed. Areas that cannot be read from the source will be >> treated as containing only zeroes. >> >> +.. option:: --target-is-zero >> + >> + Assume that reading the destination image will always return >> + zeros. This parameter is mutually exclusive with a destination image > > Late tweak now that this is in a pull request, so we may want a followup > patch, but: > > The image doesn't always return zeros after we write to it, maybe we > should tweak this sentence: > > Assume that reading the destination image will initially return all zeros. I will send a patch for this. > Also, my earlier comment about 'zeroes' one line before 'zeros' still > applies - although both spellings are valid, we look inconsistent when > we can't make up our mind within two adjacent paragraphs. If we can agree on one of "zeros" or "zeroes" then I'm happy to send a patch making it consistent everywhere. I think that given there are existing functions with "zeroes" in the name, I'd be inclined to go that way. dme. -- Why stay in college? Why go to night school?